How to pass the object property as param to Struts custom validator

This is the custom validator, has getters/setters for countryCode

public void validate(Object object) throws ValidationException {
String fieldName = getFieldName();

Object zipObj = this.getFieldValue(fieldName, object);
String country = getCountryCode();
String zipCode = (String) zipObj;

if (zipCode == null || ("".equals(zipCode))) {
  return;
}

boolean valid = false;
try {
  if ((Country.DEFAULT).equalsIgnoreCase(country)) {
    valid = Pattern.matches(US_ZIP_FORMAT, zipCode);
    int testZip = Integer.parseInt(zipCode.substring(0, 5));
    if (testZip == 0) {
      valid = false;
    }
  } else if ((Country.CANADA).equalsIgnoreCase(country)) {
    valid = Pattern.matches(CANADA_ZIP_FORMAT, zipCode);
  } else {
    valid = Pattern.matches(OTHER_ZIP_FORMAT, zipCode);
  }
} catch (Exception e) {
  logger.error("Cannot validate zip code (" + zipCode + ") for country ("
      + country + ").");
  valid = false;
}

if (!valid) {
  addFieldError(fieldName, object);
}
}

How to pass the country code back to the custom validator. This is my ActionClass-validation.xml

<validators>
<field name="address.zip">
    <field-validator type="zipValidator">
        <param name="countryCode">${address.country}</param>
        <message key="errors.zip.invalid" />
    </field-validator>
</field>
</validators>

Address object has zip and countryCode. I want to validate the zip based on the country. When I debug the above code, countryCode has the value ${address.country}.

How can I get the country property value?

You need to extend your custom validator from ValidatorSupport. Then in the implementation code you can use parse method to get the value of parameter if it's an OGNL expression.

String country = (String) parse(this.countryCode, String.class);